Mesoscale Discussion 1306

Issued

Jul 17, 2021, 1:42 PM CDT (18:42 UTC)

Expired

Jul 17, 2021, 4:15 PM CDT

In force

3 hr

Issued by

the Storm Prediction Center

Concerning

Severe potential...watch unlikely

Chance of a watch

20%

The Altus AFB radar (KFDR), 151 km from the middle of the area, began a volume at 18:43 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

702 
ACUS11 KWNS 171843
SWOMCD
SPC MCD 171842 
OKZ000-TXZ000-172115-

Mesoscale Discussion 1306
NWS Storm Prediction Center Norman OK
0142 PM CDT Sat Jul 17 2021

Areas affected...Central/Western Oklahoma into the Oklahoma and
Texas Panhandles

Concerning...Severe potential...Watch unlikely 

Valid 171842Z - 172115Z

Probability of Watch Issuance...20 percent

SUMMARY...Thunderstorms are starting to increase in coverage and
intensity across northwestern Oklahoma.  Although there is
significant uncertainty with regard to thunderstorm evolution this
afternoon, the lack of better shear will likely preclude the need
for a watch.

DISCUSSION...Elevated thunderstorms overnight and this morning over
southern Kansas have resulted in merging outflow boundaries across
northwestern Oklahoma.  With strong insolation and low 70F
dewpoints, surface-based storms have begun to initiate along the
effective boundary in a moderately unstable environment (~2000 J/kg
MLCAPE per mesoanalysis). The midlevel west-northwesterly flow (~25
knots per the VNX VWP) is enhanced by a convectively-induced
midlevel perturbation moving southeastward across the region. When
coupled with 5-10 knot southerly low-level winds ahead of the
boundary, 25-35 knots of effective bulk shear is expected to support
some storm organization and associated severe weather threat (hail
and wind for the strongest cores) through the afternoon/early
evening across western/central Oklahoma and the Texas Panhandle.
Overall, the lack of stronger shear/flow is expected to limit the
coverage of severe weather, but convective trends will continue to
be monitored.

..Jirak/Dial.. 07/17/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...TSA...OUN...LUB...AMA...

LAT...LON   36780227 36280105 35980021 35989949 36089876 36179848
            36249806 36529664 36229636 35799626 35209652 34799694
            34409768 34289859 34259974 34340054 34520119 35060192
            35790239 36010254 36270273 36780227

Mesoscale Discussions in Oklahoma, 2021Mesoscale Discussions in Texas, 2021Every mesoscale discussion in 2021

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.